<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
// $Id: DbPdo.class.php 2729 2012-02-12 04:13:34Z liu21st $

/**
 +-----------------------------
 * PDO数据库驱动类
 +-----------------------------
 */
class DbPdo extends Db{

	protected $PDOStatement = null;
	private   $table = '';

	/**
	 +----------------------------------------------------------
	 * 架构函数 读取数据库配置信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param array $config 数据库配置数组
	 +----------------------------------------------------------
	 */
	public function __construct($config=''){
		if ( !class_exists('PDO') ) {
			throw_exception(L('_NOT_SUPPERT_').':PDO');
		}
		if(!empty($config)) {
			$this->config   =   $config;
			if(empty($this->config['params'])) {
				$this->config['params'] =   array();
			}
		}

	}

	/**
	 +----------------------------------------------------------
	 * 连接数据库方法
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function connect($config='',$linkNum=0) {
		if ( !isset($this->linkID[$linkNum]) ) {
			if(empty($config))  $config =   $this->config;
			if($this->pconnect) {
				$config['params'][PDO::ATTR_PERSISTENT] = true;
			}
			//$config['params'][PDO::ATTR_CASE] = C("DB_CASE_LOWER")?PDO::CASE_LOWER:PDO::CASE_UPPER;
			try{
				$this->linkID[$linkNum] = new PDO( $config['dsn'], $config['username'], $config['password'],$config['params']);
			}catch (PDOException $e) {
				throw_exception($e->getMessage());
			}
			// 因为PDO的连接切换可能导致数据库类型不同，因此重新获取下当前的数据库类型
			$this->dbType = $this->_getDsnType($config['dsn']);
			if(in_array($this->dbType,array('MSSQL','ORACLE','IBASE','OCI'))) {
				// 由于PDO对于以上的数据库支持不够完美，所以屏蔽了 如果仍然希望使用PDO 可以注释下面一行代码
				throw_exception('由于目前PDO暂时不能完美支持'.$this->dbType.' 请使用官方的'.$this->dbType.'驱动');
			}
			$this->linkID[$linkNum]->exec('SET NAMES '.C('DB_CHARSET'));
			// 标记连接成功
			$this->connected    =   true;
			// 注销数据库连接配置信息
			if(1 != C('DB_DEPLOY_TYPE')) unset($this->config);
		}
		return $this->linkID[$linkNum];
	}

	/**
	 +----------------------------------------------------------
	 * 释放查询结果
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 */
	public function free() {
		$this->PDOStatement = null;
	}

	/**
	 +----------------------------------------------------------
	 * 执行查询 返回数据集
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  sql指令
	 +----------------------------------------------------------
	 * @return mixed
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function query($str) {
		$this->initConnect(false);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		//释放前次的查询结果
		if ( !empty($this->PDOStatement) ) $this->free();
		N('db_query',1);
		// 记录开始执行时间
		G('queryStartTime');
		$this->PDOStatement = $this->_linkID->prepare($str);
		if(false === $this->PDOStatement)
		throw_exception($this->error());
		$result =   $this->PDOStatement->execute();
		$this->debug();
		if ( false === $result ) {
			$this->error();
			return false;
		} else {
			return $this->getAll();
		}
	}

	/**
	 +----------------------------------------------------------
	 * 执行语句
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  sql指令
	 +----------------------------------------------------------
	 * @return integer
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function execute($str) {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		$flag = false;
		if($this->dbType == 'OCI')
		{
			if(preg_match("/^\s*(INSERT\s+INTO)\s+(\w+)\s+/i", $this->queryStr, $match)) {
				$this->table = C("DB_SEQUENCE_PREFIX").str_ireplace(C("DB_PREFIX"), "", $match[2]);
				$flag = (boolean)$this->query("SELECT * FROM user_sequences WHERE sequence_name='" . strtoupper($this->table) . "'");
			}
		}//modify by wyfeng at 2009.08.28
		//释放前次的查询结果
		if ( !empty($this->PDOStatement) ) $this->free();
		N('db_write',1);
		// 记录开始执行时间
		G('queryStartTime');
		$this->PDOStatement	=	$this->_linkID->prepare($str);
		if(false === $this->PDOStatement) {
			throw_exception($this->error());
		}
		$result	=	$this->PDOStatement->execute();
		$this->debug();
		if ( false === $result) {
			$this->error();
			return false;
		} else {
			$this->numRows = $result;
			if($flag || preg_match("/^\s*(INSERT\s+INTO|REPLACE\s+INTO)\s+/i", $str)) {
				$this->lastInsID = $this->getLastInsertId();
			}
			return $this->numRows;
		}
	}

	/**
	 +----------------------------------------------------------
	 * 启动事务
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return void
	 +----------------------------------------------------------
	 */
	public function startTrans() {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		//数据rollback 支持
		if ($this->transTimes == 0) {
			$this->_linkID->beginTransaction();
		}
		$this->transTimes++;
		return ;
	}

	/**
	 +----------------------------------------------------------
	 * 用于非自动提交状态下面的查询提交
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 */
	public function commit() {
		if ($this->transTimes > 0) {
			$result = $this->_linkID->commit();
			$this->transTimes = 0;
			if(!$result){
				throw_exception($this->error());
			}
		}
		return true;
	}

	/**
	 +----------------------------------------------------------
	 * 事务回滚
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function rollback() {
		if ($this->transTimes > 0) {
			$result = $this->_linkID->rollback();
			$this->transTimes = 0;
			if(!$result){
				throw_exception($this->error());
			}
		}
		return true;
	}

	/**
	 +----------------------------------------------------------
	 * 获得所有的查询数据
	 +----------------------------------------------------------
	 * @access private
	 +----------------------------------------------------------
	 * @return array
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	private function getAll() {
		//返回数据集
		$result =   $this->PDOStatement->fetchAll(constant('PDO::FETCH_ASSOC'));
		$this->numRows = count( $result );
		return $result;
	}

	/**
	 +----------------------------------------------------------
	 * 取得数据表的字段信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function getFields($tableName) {
		$this->initConnect(true);
		if(C('DB_DESCRIBE_TABLE_SQL')) {
			// 定义特殊的字段查询SQL
			$sql   = str_replace('%table%',$tableName,C('DB_DESCRIBE_TABLE_SQL'));
		}else{
			switch($this->dbType) {
				case 'MSSQL':
				case 'SQLSRV':
					$sql   = "SELECT   column_name as 'Name',   data_type as 'Type',   column_default as 'Default',   is_nullable as 'Null'
        FROM    information_schema.tables AS t
        JOIN    information_schema.columns AS c
        ON  t.table_catalog = c.table_catalog
        AND t.table_schema  = c.table_schema
        AND t.table_name    = c.table_name
        WHERE   t.table_name = '$tableName'";
					break;
				case 'SQLITE':
					$sql   = 'PRAGMA table_info ('.$tableName.') ';
					break;
				case 'ORACLE':
				case 'OCI':
					$sql   = "SELECT a.column_name \"Name\",data_type \"Type\",decode(nullable,'Y',0,1) notnull,data_default \"Default\",decode(a.column_name,b.column_name,1,0) \"pk\" "
					."FROM user_tab_columns a,(SELECT column_name FROM user_constraints c,user_cons_columns col "
					."WHERE c.constraint_name=col.constraint_name AND c.constraint_type='P' and c.table_name='".strtoupper($tableName)
					."') b where table_name='".strtoupper($tableName)."' and a.column_name=b.column_name(+)";
					break;
				case 'PGSQL':
					$sql   = 'select fields_name as "Name",fields_type as "Type",fields_not_null as "Null",fields_key_name as "Key",fields_default as "Default",fields_default as "Extra" from table_msg('.$tableName.');';
					break;
				case 'IBASE':
					break;
				case 'MYSQL':
				default:
					$sql   = 'DESCRIBE '.$tableName;//备注: 驱动类不只针对mysql，不能加``
			}
		}
		$result = $this->query($sql);
		$info   =   array();
		if($result) {
			foreach ($result as $key => $val) {
				$val['Name'] = isset($val['name'])?$val['name']:$val['Name'];
				$val['Type'] = isset($val['type'])?$val['type']: $val['Type'];
				$name= strtolower(isset($val['Field'])?$val['Field']:$val['Name']);
				$info[$name] = array(
                    'name'    => $name ,
                    'type'    => $val['Type'],
                    'notnull' => (bool)(((isset($val['Null'])) && ($val['Null'] === '')) || ((isset($val['notnull'])) && ($val['notnull'] === ''))), // not null is empty, null is yes
                    'default' => isset($val['Default'])? $val['Default'] :(isset($val['dflt_value'])?$val['dflt_value']:""),
                    'primary' => isset($val['Key'])?strtolower($val['Key']) == 'pri':(isset($val['pk'])?$val['pk']:false),
                    'autoinc' => isset($val['Extra'])?strtolower($val['Extra']) == 'auto_increment':(isset($val['Key'])?$val['Key']:false),
				);
			}
		}
		return $info;
	}

	/**
	 +----------------------------------------------------------
	 * 取得数据库的表信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function getTables($dbName='') {
		if(C('DB_FETCH_TABLES_SQL')) {
			// 定义特殊的表查询SQL
			$sql   = str_replace('%db%',$dnName,C('DB_FETCH_TABLES_SQL'));
		}else{
			switch($this->dbType) {
				case 'ORACLE':
				case 'OCI':
					$sql   = 'SELECT table_name FROM user_tables';
					break;
				case 'MSSQL':
				case 'SQLSRV':
					$sql   = "SELECT TABLE_NAME	FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE'";
					break;
				case 'PGSQL':
					$sql   = "select tablename as Tables_in_test from pg_tables where  schemaname ='public'";
					break;
				case 'IBASE':
					// 暂时不支持
					throw_exception(L('_NOT_SUPPORT_DB_').':IBASE');
					break;
				case 'SQLITE':
					$sql   = "SELECT name FROM sqlite_master WHERE type='table' "
					. "UNION ALL SELECT name FROM sqlite_temp_master "
					. "WHERE type='table' ORDER BY name";
					break;
				case 'MYSQL':
				default:
					if(!empty($dbName)) {
						$sql    = 'SHOW TABLES FROM '.$dbName;
					}else{
						$sql    = 'SHOW TABLES ';
					}
			}
		}
		$result = $this->query($sql);
		$info   =   array();
		foreach ($result as $key => $val) {
			$info[$key] = current($val);
		}
		return $info;
	}

	/**
	 +----------------------------------------------------------
	 * limit分析
	 +----------------------------------------------------------
	 * @access protected
	 +----------------------------------------------------------
	 * @param mixed $lmit
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	protected function parseLimit($limit) {
		$limitStr    = '';
		if(!empty($limit)) {
			switch($this->dbType){
				case 'PGSQL':
				case 'SQLITE':
					$limit  =   explode(',',$limit);
					if(count($limit)>1) {
						$limitStr .= ' LIMIT '.$limit[1].' OFFSET '.$limit[0].' ';
					}else{
						$limitStr .= ' LIMIT '.$limit[0].' ';
					}
					break;
				case 'MSSQL':
				case 'SQLSRV':
					break;
				case 'IBASE':
					// 暂时不支持
					break;
				case 'ORACLE':
				case 'OCI':
					break;
				case 'MYSQL':
				default:
					$limitStr .= ' LIMIT '.$limit.' ';
			}
		}
		return $limitStr;
	}

	/**
	 +----------------------------------------------------------
	 * 关闭数据库
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 */
	public function close() {
		$this->_linkID = null;
	}

	/**
	 +----------------------------------------------------------
	 * 数据库错误信息
	 * 并显示当前的SQL语句
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	public function error() {
		if($this->PDOStatement) {
			$error = $this->PDOStatement->errorInfo();
			$this->error = $error[2];
		}else{
			$this->error = '';
		}
		if($this->debug && '' != $this->queryStr){
			$this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
		}
		return $this->error;
	}

	/**
	 +----------------------------------------------------------
	 * SQL指令安全过滤
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  SQL指令
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	public function escapeString($str) {
		switch($this->dbType) {
			case 'PGSQL':
			case 'MSSQL':
			case 'SQLSRV':
			case 'IBASE':
			case 'MYSQL':
				return addslashes($str);
			case 'SQLITE':
			case 'ORACLE':
			case 'OCI':
				return str_ireplace("'", "''", $str);
		}
	}

	/**
	 +----------------------------------------------------------
	 * 获取最后插入id
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return integer
	 +----------------------------------------------------------
	 */
	public function getLastInsertId() {
		switch($this->dbType) {
			case 'PGSQL':
			case 'SQLITE':
			case 'MSSQL':
			case 'SQLSRV':
			case 'IBASE':
			case 'MYSQL':
				return $this->_linkID->lastInsertId();
			case 'ORACLE':
			case 'OCI':
				$sequenceName = $this->table;
				$vo = $this->query("SELECT {$sequenceName}.currval currval FROM dual");
				return $vo?$vo[0]["currval"]:0;
		}
	}

}